The present invention relates generally to exercise devices which are portable for use in any setting, and more particularly to a portable exercise device which utilizes frictional forces as opposed to spring or compressive forces to provide the necessary resistance to the unwinding of a coacting exercise cord or other contrivance employed to facilitate in exercising the various muscles of the human body.
Portable exercise devices are well known in the prior art, as is shown by U.S. Pat. Nos. 4,557,480; 4,174,832; 4,114,875; and 3,885,789. These devices all provide rotatable pulleys having a length of cord operatively wound thereabout and provide the necessary resistance to unwinding the exercise cord by either establishing a compressive force against the cord itself or by winding the cord about one or a series of capstands. Such structural limitations give rise to various operational limitations and further cause the exercise cord to wear excessively during the use of the exercise device, thus reducing the efficiency and life of the exercise device. One skilled in the art will readily recognize that the prior art methods of providing resistance to the unwinding of the exercise cord militate against accurate adjustment of the resistance as well as limiting the degree of resistance which can be attained.
The prior art is also deficient in regard to providing a device which can be used effectively when the device is employed independently of a fixed structure. Although a minority of the prior art devices can be used in such a manner, these devices are extremely bulky and difficult to maneuver. An analysis of U.S. Pat. Nos. 4,010,948 and 4,114,875 reveals that a full extension of the muscle being exercised can not be established utilizing the devices disclosed therein because the "fixed" handle is not rigidly secured to the housing containing the exercise cord. Further, a complete program of exercise can not be practiced with the prior art devices because of their size, weight and reduced capabilities when employed independently of a fixed structure.
Thus, it is clear that the shortcomings evident in the prior art warrant improvement with respect to the method of providing resistance to the unwinding of the exercise cord, the compactness and operational maneuverability of the entire device, and other features as will be addressed herein.
The present invention provides a portable exercise device which is compact in size and weight, yet is capable of providing a large easily adjusted range of resistive forces by virtue of frictional forces being applied to a rotatable surface operatively engageable with a rotatable sheave about which an exercise cord is wound. A second embodiment provides a fixed handle integrally formed with the housing containing the exercise cord and means for providing a resistance to unwinding the cord, and an exercise handle which is separable from the housing at the end remote from the fixed handle.